Although asthma is a manageable disease, amenable to primary care, it has become an increasingly common cause of hospital admissions among inner-city children. Factors including poor access to health care contribute to high hospitalization rates. Though numerous interventions have been reported, they have not been widely adopted or evaluated in poor communities. The Montefiore Medical Center School Health Program operates 11 school-based health centers (SBHCs) serving 10,000 disadvantaged public school students in the Bronx, New York. SBHCs overcome many access barriers and provide an opportunity to engage children in the appropriate use of outpatient services. They also offer an ideal setting for the introduction and evaluation of an asthma intervention designed to reduce morbidity and costs. The goals of this three-year study are: 1) to determine whether the addition of a pro-active outreach component to the traditional model of primary care in a school setting will have a measurable effect on the health status and school performance of children with asthma; and, 2) to examine the economic implications of implementing this pro-active model of asthma care in SBHCs. This project will involve six Bronx elementary schools--two schools that do not have SBHCs, and four that have SBHCs run by the Montefiore Medical Center School Health Program. Two of the schools with SBHCs will be designated as pro-active or intervention sites. Outcomes will be compared according to three models of school health: (1) the control model, for schools without SBHCs; (2) the traditional model, for schools with SBHCs treating children who present for care; and, (3) the pro-active model for schools with SBHCs and aggressive outreach programs. Demographic and socioeconomic characteristics will be collected at baseline and at regular intervals to adjust for variation between the populations, and outcomes of interest compared over a three year period. In addition, relevant process data will be gathered to document successful elements of the intervention to facilitate integration with routine clinical practice.